High-pressure x-ray diffraction, absorption, luminescence, and Raman-scattering study of Cs{sub 2}MoS{sub 4}
- Texas Center for Superconductivity, University of Houston, Houston, Texas 77204-5932 (United States)
- Hochdrucklabor bei der Universitaet Potsdam, Telegrafenberg A43, D-14473 Potsdam (Germany)
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 (United States)
- CHESS, Wilson Laboratory, Cornell University, Ithaca, New York 14853 (United States)
- Department of Physics, Colorado State University, Fort Collins, Colorado 80523 (United States)
Cesium thiomolybdate, Cs{sub 2}MoS{sub 4}, has been investigated at pressures up to 12 GPa. Two phase transitions have been detected by absorption measurements, Raman spectroscopy, and energy dispersive x-ray diffraction. The first phase transition to a monoclinic phase II [a=14.061(9) {Angstrom}, b=11.552(7) {Angstrom}, c=9.852(6) {Angstrom}, {beta}=97.14(6){degree}] has been observed at 8.0 GPa. The second transition at 9.7 GPa has been observed from the monoclinic phase II to an orthorhombic phase III [a=12.085(4) {Angstrom}, b=15.707(6) {Angstrom}, c=11.828(5) {Angstrom}]. Absorption and luminescence measurements have indicated an increase in the absorption edge energy with pressure up to {approximately}3 GPa. At pressures greater than 3.5 GPa, the absorption energy decreases. Raman spectroscopy has revealed a low-frequency phonon mode with a negative pressure shift in the low-pressure phase I. The pressure-temperature phase diagram has been determined up to 250{degree}C. The transition pressures decrease linearly with slopes of {approximately}{minus}0.013 GPa/{degree}C. Models for the pressure-induced structural and electronic transitions are proposed. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 489287
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 5 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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